The present invention is directed to methods and devices for improving the appearance of tissue such as skin.
A known method of improving the appearance of tissue by removing fat is liposuction. Liposuction has become a widely accepted procedure for removing undesirable localized fat tissue, especially in areas that may be unresponsive to diet or exercise. This procedure is effective in removing excess accumulations of fat from various parts of the body such as the face, neck, waist, buttocks, thighs, inner upper thighs, knees, ankles, lower legs and upper arms.
Body fat varies in structure and composition in different regions of the body. Much of the subcutaneous fat in a normal, healthy human is generally arranged to form a thin blanket-like layer. In some areas of the body fat cells exist in large subcutaneous deposits.
The most common liposuction technique uses a blunt tip cannula positioned between the skin and muscle. Through an incision site, the cannula is repeatedly thrust radially while suction from a vacuum source is transmitted down the shaft of the cannula to the distal opening(s). As adipose tissue is freed it is aspirated through one or more holes in the side of the cannula. By controlling the quantity and location of adipose tissue removal, an enhanced surface contour or reduction in volume can be achieved.
One problem with conventional liposuction is that the mobility of the cannula is often limited by septae, which are fibrous connections between the skin and muscle layers. These septae cannot be easily severed by blunt liposuction cannulae, hence, the path of least resistance for the cannula is in tunnels or passageways in between the septae. In areas where the septae are dense the ability to access all the desired fat can be limited, especially further from the incision site. Consequently, many physicians will access the same area from two incision sites to try and address fat made inaccessible by septae. However, in practice many liposuction practioners still identify areas where excess fat exists but cannot be removed.
Another method of improving the appearance of tissue is to reduce the dimpling effect of cellulite. Cellulite is believed to be caused by the same fibrous tissue or septae which hamper liposuction procedures. One method of reducing the dimpled appearance of cellulite is to cut the septae using a needle having a sharp tip. The needle is dragged through tissue numerous times so that the sharp tip of the needle cuts the septae.
A problem with the above described method for reducing the appearance of cellulite is that the needle is highly inefficient when the desired treatment area is large. For example, a 10 cm by 10 cm area of skin, which is common in terms of the distribution of cellulite on an adult human, will likely contain 100 to 300 septae. Further, given the size of the needle and the distribution of septae, a 10 cm by 10 cm area of skin would require numerous incision sites in order to cut all the septae in that area. Multiple incision sites are undesirable to the patient, and time consuming for the physician.